This invention relates to an optical disc on which video data, audio data, and the like are recorded, an optical disc recording apparatus for recording data onto the optical disc, and an optical disc reproducing apparatus for reproducing the data recorded on the optical disc.
In recent years, moving-picture-compatible optical disc playback systems have been developed which play back an optical disc on which video data, audio data, and the like have been recorded. They have been widely used in the form of, for example, LDs (Laser Discs) or video CDs for the purpose of reproducing movie software or karaoke.
In this connection, the DVD (Digital Versatile Disc) standard employing the internationally standardized MPEG-2 (Motion Picture Experts Group 2) scheme and the AC (Audio Compression)-3 scheme has been proposed.
The DVD standard supports MPEG-2 for moving picture compression scheme and AC-3 audio and MPEG audio for audio recording scheme according to the MPEG-2 system layer architecture. The DVD standard further supports sub-picture data, obtained by runlength compressing the bit map data for subtitles, and special playback control data (navigation pack) such as fast-forward playback or fast-rewind playback data.
Furthermore, the DVD standard supports ISO 9660 and micro UDF (or UDF Bridge) to allow computers to read data of DVD.
Presently, however, the DVD standard takes no account of home recording/reproducing systems. When home recording/reproducing systems are constructed according to the standard, the following problem arise.
In DVD, information on title is defined as text information.
The text information, which is used for retrieval or search, has not been used much, because the DVD-ROM video has a menu (menu pictures) the title producer created, such as VMGM (video manager menu) or VTSM (video title set menu). In home recording/reproducing systems, however, a menu cannot be entered beforehand to record TV programs or moving pictures and still pictures (photographic data) from a camera into a DVD-RAM. Thus, retrieval or search using the text information becomes important.
In the DVD-ROM video, however, the text information has been created, taking no account of language. More specifically, in European countries and Asian countries, language differs from one TV station to another or from one program to another. Additionally, assume a case where a person goes abroad, carrying a DVD recorder with him or her, and does video-recording where he or she is staying. Under this assumption, if it is unknown which language the text information was recorded, the DVD recorder (or player) cannot judge whether or not a character generator (e.g., kanji ROM) corresponding to its language code is provided therein, when the text information is decoded. This makes the decoding difficult. Moreover, when the text information does not correspond to the language, information retrieval (search) and the like cannot be performed at all.
The present invention aims to remove the drawback that, when the language in the text information corresponding to the video data to be recorded varies each time recording is done on a video-data-recording optical disc (or information storage medium), this cannot be dealt with and text retrieval cannot be performed.
A first object of the present invention is to provide an optical disc (or information storage medium) which enables multilingual text retrieval.
A second object of the present invention is to provide an apparatus for recording information on the optical disc (or information storage medium).
A third object of the present invention is to provide an apparatus for reproducing the recorded information from the optical disc (or information storage medium).
To accomplish the first object, an optical disc (or an information storage medium) according to the present invention has a management area (RTR. IFO of FIG. 13D/RTR_VMG of FIG. 13E) and a data area (1012 to 1016 in FIG. 13D). In the data area (1012 to 1016), data (including video data and audio data) is separated into one or more sequences (PGCs), which are then recorded. Each sequence (PGC) is composed of one or more programs corresponding to one or more cells (see FIG. 15).
Here, one cell corresponds to one or more data unit (VOBU in FIG. 3). One data unit (VOBU) includes one or more packs of pictures or sound to be reproduced in a period of time in a specific range (0.5 to 1.2 seconds).
In the management area (RTR_VMG), a sequence management table (PGCIT of FIG. 6, 1752 in FIG. 16, ORG_PGCI or UD_PGCIT of FIG. 17)) for managing program sequences by determining the playback sequence (or an order of playback) of the cells and a program management table (PGC_PGI of FIG. 6, PGI # in FIG. 15 or 17) exist independently or partially overlap with each other.
In the program management table (PGI #1), first text information (PRM_TXTI) expressed in alphanumeric characters (e.g., the ASCII code) is recorded.
In a specific area (TXTDT_MG in FIG. 4 or FIG. 16) different from the program management table (PGI #) in the management area, second text information (IT_TXT) is recorded in the same as or a different language from that of the first text information (PRM_TXTI).
In the optical disc, the first text information (PRM_TXTI) includes first retrieval information (ST23 in FIG. 10) usable in searching for the programs.
Additionally, in the optical disc, the second text information (IT_TXT) includes second retrieval information (ST25 in FIG. 10) usable in searching for the programs.
Furthermore, in the optical disc, the second text information (IT_TXT in FIG. 12) includes an identification code (IDCD), the size of text information (TXT_SZ), and the body of text information (TXT).
Alternatively, in the optical disc, the second text information (IT_TXT in FIG. 12) includes an identification code (IDCD) and the size of text information (TXT_SZ).
Furthermore, in the optical disc, the sequence management table (VOB sequence information 1752 in FIG. 16) includes a search pointer (PL_SRP #) which points at a specific point in the program sequence (VOB sequence) and includes the first text information (PRM_TXTI).
Moreover, in the optical disc, the specific area (TXTDT_MG in FIG. 16) is included in the management area (RTR_VMG) and includes the second text information (IT_TXT) as sub-information for the first text information (PRM_TXTI).
Additionally, in the optical disc, the first text information (PRM_TXTI) and second text information (IT_TXT) can be used in searching for the programs and a search using the first text information (PRM_TXTI) has priority of search over a search using the second text information (IT_TXT) (in FIG. 10, ST25 using IT_TXT is after the process at ST18 using PRM_TXTI).
In addition, in the optical disc, the management area (RTR_VMG) includes a management table (CI in FIG. 17) for managing the cells, and text information (PRM_TXTI) expressed in alphanumeric characters is recorded in the cell management table (M_CI or S_CI in FIG. 17).
Here, the first text information (PRM_TXTI) can include at least one of video-recording start date and time, video-recording end date and time, a source name, and a channel number.
To achieve the second object, a recording apparatus according to the present invention uses an optical disc (10) having a management area (RTR_VMG in FIG. 13E) and a data area (1012 to 1016 in FIG. 13D) in which one or more programs have been recorded, the management area (RTR_VMG) including a sequence management table (ORG_PGCI or UD_PGCIT) for managing the sequence of the programs and a program management table (PGI) for managing the programs.
The recording apparatus comprises: first recording means (101 to 104 in FIG. 1, ST4 in FIG. 9) for recording data in programs into the data area on the optical disc; second recording means (101 to 104 in FIG. 1, ST2 in FIG. 9) for recording first text information (PRM_TXTI) expressed in alphanumeric characters and usable in searching for the programs into the program management table (PGI) on the optical disc; and third recording means (101 to 104 in FIG. 1, ST3 in FIG. 9) for recording second text information (IT_TXT) usable in searching for the programs into an area different from the program management table in the management area on the optical disc.
In the recording apparatus, the second text information (IT_TXT) is expressed in the same language as that of the first text information (PRM_TXTI).
Alternatively, in the recording apparatus, the second text information (IT_TXT) is expressed in a different language from that of the first text information (PRM_TXTI).
Furthermore, in the recording apparatus, the second and third recording means (ST2, ST3) record in such a manner that a search using the first text information (PRM_TXTI) has priority of search over a search using the second text information (IT_TXT) (in FIG. 10, ST25 using IT_TXT is after the process at ST18 using PRM_TXTI).
To accomplish the third object, a reproducing apparatus according to the present invention uses an optical disc (10) having a management area (RTR_VMG in FIG. 13E) and a data area (1012 to 1016 in FIG. 13D) in which one or more programs have been recorded, the management area (RTR_VMG) including a sequence management table (ORG_PGCI or UD_PGCIT) for managing the sequence of the programs and a program management table (PGI) for managing the programs.
The reproducing apparatus comprises: an input section (120 in FIG. 1, ST23 in FIG. 10) for inputting at least one of video-recording date and channel number as text information (TEXT in FIG. 12); a retrieving section (101 in FIG. 11, ST16 in FIG. 10) for retrieving a program (the program NONFICTION in FIG. 11 or 12) to be reproduced by comparing the inputted text information (TEXT=video-recording date and/or channel number) with primary text information (PRM_TXTI) recorded in the program management table (PGI); a selecting section (101 in FIG. 1, ST19 in FIG. 10) for selecting one (TEXT in FIG. 12) of the pieces of the text information (video-recording date and time lists 1 to 3 in FIG. 11) about the retrieved program (NONFICTION) to be reproduced; and a reproducing section (101 to 106 in FIG. 1, ST20 in FIG. 10) for reproducing the data for the program (NONFICTION) corresponding to the selected piece of the text information (TEXT in FIG. 12).
The reproducing apparatus further comprises a second retrieving section (101 in FIG. 1, ST25 in FIG. 10) for retrieving a program using text information different from the primary text information (PRM_TXTI).
In the reproducing apparatus, a search using the primary text information (PRM_TXTI) has priority over a search using the different text information (IT_TXT) (in FIG. 10, ST25 using IT_TXT is after the process at ST18 using PRM_TXTI).
The reproducing apparatus reproduces the first text information (PRM_TXTI) from the optical disc (101 to 106 in FIG. 1, ST15 in FIG. 10).
The reproducing apparatus reproduces the second text information (IT_TXT) from the optical disc (101 to 106 in FIG. 1, ST25 in FIG. 10).
Furthermore, the reproducing apparatus reproduces the contents of records (TXTDT_MG in FIG. 4, PGI, CI in FIG. 6) in the management area (RTR_VMG) from the optical disc (101 to 106 in FIG. 1, ST11 in FIG. 10).
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.